upgrade watchdog service to scheduled task

ee/watchdog/controller_windows.go

@@ -9,8 +9,6 @@ import (
 	"fmt"
 	"log"
 	"log/slog"
-	"os"
-	"path/filepath"
 	"slices"
 	"strings"
 	"time"
@@ -217,22 +215,6 @@ func (wc *WatchdogController) ServiceEnabledChanged(enabled bool) {
 	wc.slogger.Log(ctx, slog.LevelInfo, "completed watchdog scheduled task installation")
 }
 
-func getExecutablePath(identifier string) (string, error) {
-	if strings.TrimSpace(identifier) == "" {
-		identifier = launcher.DefaultLauncherIdentifier
-	}
-
-	binDirBase := fmt.Sprintf(`C:\Program Files\Kolide\Launcher-%s\bin`, identifier)
-	launcherBin := filepath.Join(binDirBase, "launcher.exe")
-	// do some basic sanity checking to prevent installation from a bad path
-	_, err := os.Stat(launcherBin)
-	if err != nil {
-		return "", err
-	}
-
-	return launcherBin, nil
-}
-
 // installWatchdogTask registers our watchdog subcommand as a scheduled task.
 // see inline comments for details on various settings, but here is a general overview:
 // Triggers:
@@ -246,7 +228,8 @@ func installWatchdogTask(identifier, configFilePath string) error {
 	}
 
 	taskName := launcher.TaskName(identifier, watchdogTaskType)
-	// init COM
+	// init COM - we discard the error returned by CoInitialize because it
+	// harmlessly returns S_FALSE if we call it more than once
 	ole.CoInitialize(0)
 	defer ole.CoUninitialize()
 
@@ -299,7 +282,7 @@ func installWatchdogTask(identifier, configFilePath string) error {
 	regInfo := regInfoProp.ToIDispatch()
 	defer regInfo.Release()
 
-	if _, err = oleutil.PutProperty(regInfo, "Description", "Kolide agent waker"); err != nil {
+	if _, err = oleutil.PutProperty(regInfo, "Description", "Kolide agent restarter"); err != nil {
 		return fmt.Errorf("setting reginfo description: %w", err)
 	}
 
@@ -481,7 +464,7 @@ func installWatchdogTask(identifier, configFilePath string) error {
 	execAction := execActionTemplate.ToIDispatch()
 	defer execAction.Release()
 
-	installedExePath, err := getExecutablePath(identifier)
+	installedExePath, err := launcher.GetOriginalLauncherExecutablePath(identifier)
 	if err != nil {
 		return fmt.Errorf("determining watchdog executable path: %w", err)
 	}
@@ -521,7 +504,8 @@ func RemoveWatchdogTask(identifier string) error {
 	}
 
 	taskName := launcher.TaskName(identifier, watchdogTaskType)
-	// init COM
+	// init COM - we discard the error returned by CoInitialize because it
+	// harmlessly returns S_FALSE if we call it more than once
 	ole.CoInitialize(0)
 	defer ole.CoUninitialize()
 
@@ -571,7 +555,8 @@ func watchdogTaskExists(identifier string) (bool, error) {
 	}
 
 	taskName := launcher.TaskName(identifier, watchdogTaskType)
-	// init COM
+	// init COM - we discard the error returned by CoInitialize because it
+	// harmlessly returns S_FALSE if we call it more than once
 	ole.CoInitialize(0)
 	defer ole.CoUninitialize()
 

pkg/launcher/paths.go

@@ -1,6 +1,7 @@
 package launcher
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -156,3 +157,32 @@ func nonEmptyFileExists(path string) (bool, error) {
 
 	return fileInfo.Size() > 0, nil
 }
+
+// GetOriginalLauncherExecutablePath is a convenience function to determine and verify the location of
+// the originally installed launcher executable. it uses the identifier to generate the expected path and
+// verifies file presence before returning the path
+func GetOriginalLauncherExecutablePath(identifier string) (string, error) {
+	if strings.TrimSpace(identifier) == "" {
+		identifier = DefaultLauncherIdentifier
+	}
+
+	var binDirBase string
+	var launcherExeName string
+
+	switch runtime.GOOS {
+	case "windows":
+		binDirBase = fmt.Sprintf(`C:\Program Files\Kolide\Launcher-%s\bin`, identifier)
+		launcherExeName = "launcher.exe"
+	default:
+		binDirBase = fmt.Sprintf(`/usr/local/%s/bin`, identifier)
+		launcherExeName = "launcher"
+	}
+
+	launcherBin := filepath.Join(binDirBase, launcherExeName)
+	// do some basic sanity checking to prevent installation from a bad path
+	if exists, err := nonEmptyFileExists(launcherBin); err != nil || !exists {
+		return "", err
+	}
+
+	return launcherBin, nil
+}